Rare copy number variation in autoimmune Addison's disease

Autoimmune Addison's disease (AAD) is a rare but life-threatening endocrine disorder caused by an autoimmune destruction of the adrenal cortex. A previous genome-wide association study (GWAS) has shown that common variants near immune-related genes, which mostly encode proteins participating in the immune response, affect the risk of developing this condition. However, little is known about the contribution of copy number variations (CNVs) to AAD susceptibility. We used the genome-wide genotyping data from Norwegian and Swedish individuals (1,182 cases and 3,810 controls) to investigate the putative role of CNVs in the AAD aetiology. Although the frequency of rare CNVs was similar between cases and controls, we observed that larger deletions (>1,000 kb) were more common among patients (OR = 4.23, 95% CI 1.85-9.66, p = 0.0002). Despite this, none of the large case-deletions were conclusively pathogenic, and the clinical presentation and an AAD-polygenic risk score were similar between cases with and without the large CNVs. Among deletions exclusive to individuals with AAD, we highlight two ultra-rare deletions in the genes LRBA and BCL2L11, which we speculate might have contributed to the polygenic risk in these carriers. In conclusion, rare CNVs do not appear to be a major cause of AAD but further studies are needed to ascertain the potential contribution of rare deletions to the polygenic load of AAD susceptibility.

A novel mutation in the NNT gene causing familial glucocorticoid deficiency, with a literature review

Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder characterized by low cortisol levels despite elevated adrenocorticotropin (ACTH). Mineralocorticoid secretion is classically normal. Clinical manifestations are secondary to low cortisol levels (recurrent hypoglycemia, chronic asthenia, failure to thrive, seizures) and high levels of ACTH (cutaneous-mucosal hyperpigmentation). FGD is often caused by mutations in the ACTH melanocortin 2 receptor gene (MC2R, 18p11.21, FGD type 1) or melanocortin receptor 2 accessory protein gene (MRAP, 21q22.11, FGD type 2). But mutations have also been described in other genes: the steroidogenic acute regulatory protein (STAR, 8q11.2q13.2, FGD type 3), nicotinamide nucleotide transhydrogenase (NNT, 5p12, FGD type 4) and thioredoxin reductase 2 genes (TXNRD2, 22q11.21, FGD type 5). We report the case of a 3-year-old boy recently diagnosed with FGD type 4 due to a novel mutation in NNT gene. A homozygous variant in exon 18 of the NNT gene, NM_012343.3:c.2764C>T, p.(Arg922*), determines a stop codon and, consequently, a non-functional truncated protein or absence of protein due to the nonsense-mediated decay (NMD) mechanism. We review the recent literature on NNT mutations and clinical presentations, which are broader than suspected. This disorder can result in significant morbidity and is potentially fatal if untreated. Precise diagnosis allows correct treatment and follow-up.

Regulatory T cells in autoimmune primary adrenal insufficiency

Primary adrenal insufficiency (PAI) is most often caused by an autoimmune destruction of the adrenal cortex resulting in failure to produce cortisol and aldosterone. The aetiology is thought to be a combination of genetic and environmental risk factors, leading to breakdown of immunological tolerance. Regulatory T cells (Tregs) are deficient in many autoimmune disorders, but it is not known whether they contribute to development of PAI. We aimed to investigate the frequency and function of naive and expanded Tregs in patients with PAI and polyendocrine syndromes compared to age- and gender-matched healthy controls. Flow cytometry was used to assess the frequency and characterize functional markers of blood Tregs in PAI (N = 15). Expanded Treg suppressive abilities were assessed with a flow cytometry based suppression assay (N = 20), while bulk RNA-sequencing was used to examine transcriptomic differences (N = 16) and oxygen consumption rate was measured by a Seahorse cell metabolic assay (N = 11). Our results showed that Treg frequency and suppressive capacity were similar between patients and controls. An increased expression of killer-cell leptin-like receptors and mitochondrial genes was revealed in PAI patients, but their expanded Tregs did not display signs of mitochondrial dysfunction. Our findings do not support a clear role for Tregs in the contribution of PAI development.

Genetic and phenotypic spectrum of non-21-hydroxylase-deficiency primary adrenal insufficiency in childhood: data from 111 Chinese patients

BACKGROUND

Primary adrenal insufficiency (PAI) is a rare but life-threatening condition. Differential diagnosis of numerous causes of PAI requires a thorough understanding of the condition.

METHODS

To describe the genetic composition and presentations of PAI. The following data were collected retrospectively from 111 patients with non-21OHD with defined genetic diagnoses: demographic information, onset age, clinical manifestations, laboratory findings and genetic results. Patients were divided into four groups based on the underlying pathogenesis: (1) impaired steroidogenesis, (2) adrenal hypoplasia, (3) resistance to adrenocorticotropic hormone (ACTH) and (4) adrenal destruction. The age of onset was compared within the groups.

RESULTS

Mutations in the following genes were identified: NR0B1 (n=39), STAR (n=33), CYP11B1 (n=12), ABCD1 (n=8), CYP17A1 (n=5), HSD3B2 (n=4), POR (n=4), MRAP (n=2), MC2R (n=1), CYP11A1 (n=1), LIPA (n=1) and SAMD9 (n=1). Frequent clinical manifestations included hyperpigmentation (73.0%), dehydration (49.5%), vomiting (37.8%) and abnormal external genitalia (23.4%). Patients with adrenal hypoplasia typically presented manifestations earlier than those with adrenal destruction but later than those with impaired steroidogenesis (both p<0.01). The elevated ACTH (92.6%) and decreased cortisol (73.5%) were the most common laboratory findings. We generated a differential diagnosis flowchart for PAI using the following clinical features: 17-hydroxyprogesterone, very-long-chain fatty acid, external genitalia, hypertension and skeletal malformation. This flowchart identified 84.8% of patients with PAI before next-generation DNA sequencing.

CONCLUSIONS

STAR and NR0B1 were the most frequently mutated genes in patients with non-21OHD PAI. Age of onset and clinical characteristics were dependent on aetiology. Combining clinical features and molecular tests facilitates accurate diagnosis.

X-linked adrenoleukodystrophy and primary adrenal insufficiency

X-linked adrenoleukodystrophy (X-ALD; OMIM:300100) is a progressive neurodegenerative disorder caused by a congenital defect in the ATP-binding cassette transporters sub-family D member 1 gene (ABCD1) producing adrenoleukodystrophy protein (ALDP). According to population studies, X-ALD has an estimated birth prevalence of 1 in 17.000 subjects (considering both hemizygous males and heterozygous females), and there is no evidence that this prevalence varies among regions or ethnic groups. ALDP deficiency results in a defective peroxisomal β-oxidation of very long chain fatty acids (VLCFA). As a consequence of this metabolic abnormality, VLCFAs accumulate in nervous system (brain white matter and spinal cord), testis and adrenal cortex. All X-ALD affected patients carry a mutation on the ABCD1 gene. Nevertheless, patients with a defect on the ABCD1 gene can have a dramatic difference in the clinical presentation of the disease. In fact, X-ALD can vary from the most severe cerebral paediatric form (CerALD), to adult adrenomyeloneuropathy (AMN), Addison-only and asymptomatic forms. Primary adrenal insufficiency (PAI) is one of the main features of X-ALD, with a prevalence of 70% in ALD/AMN patients and 5% in female carriers. The pathogenesis of X-ALD related PAI is still unclear, even if a few published data suggests a defective adrenal response to ACTH, related to VLCFA accumulation with progressive disruption of adrenal cell membrane function and ACTH receptor activity. The reason why PAI develops only in a proportion of ALD/AMN patients remains incompletely understood. A growing consensus supports VLCFA assessment in all male children presenting with PAI, as early diagnosis and start of therapy may be essential for X-ALD patients. Children and adults with PAI require individualized glucocorticoid replacement therapy, while mineralocorticoid therapy is needed only in a few cases after consideration of hormonal and electrolytes status. Novel approaches, such as prolonged release glucocorticoids, offer potential benefit in optimizing hormonal replacement for X-ALD-related PAI. Although the association between PAI and X-ALD has been observed in clinical practice, the underlying mechanisms remain poorly understood. This paper aims to explore the multifaceted relationship between PAI and X-ALD, shedding light on shared pathophysiology, clinical manifestations, and potential therapeutic interventions.

Autoimmune primary adrenal insufficiency -current diagnostic approaches and future perspectives

The adrenal glands are small endocrine glands located on top of each kidney, producing hormones regulating important functions in our body like metabolism and stress. There are several underlying causes for adrenal insufficiency, where an autoimmune attack by the immune system is the most common cause. A number of genes are known to confer early onset adrenal disease in monogenic inheritance patterns, usually genetic encoding enzymes of adrenal steroidogenesis. Autoimmune primary adrenal insufficiency is usually a polygenic disease where our information recently has increased due to genome association studies. In this review, we go through the physiology of the adrenals before explaining the different reasons for adrenal insufficiency with a particular focus on autoimmune primary adrenal insufficiency. We will give a clinical overview including diagnosis and current treatment, before giving an overview of the genetic causes including monogenetic reasons for adrenal insufficiency and the polygenic background and inheritance pattern in autoimmune adrenal insufficiency. We will then look at the autoimmune mechanisms underlying autoimmune adrenal insufficiency and how autoantibodies are important for diagnosis. We end with a discussion on how to move the field forward emphasizing on the clinical workup, early identification, and potential targeted treatment of autoimmune PAI.

Predisposing factors for adrenal crisis in chronic adrenal insufficiency: a case-control study

OBJECTIVE

This study aims to identify susceptibility markers for adrenal crises (AC) in educated patients with chronic adrenal insufficiency (AI).

DESIGN

A case-control study involving 66 patients with AI analyzing the impact of glucocorticoid and mineralocorticoid exposure, adrenomedullary function, inflammatory parameters, and educational status on AC frequency. Patients were categorized into low (n = 32) and high (n = 34) AC frequency groups based on AC occurrence (below or 2 times above the average of the reported AC frequency of 8.3 AC/100 patient-years in a previous prospective study).

METHODS

Parameters, including cortisol plasma profile and urinary steroid excretion after administration of the morning glucocorticoid dose, 24-h urinary steroid profiling, salivary cortisol profiling, and hair cortisol, estimated cortisol exposure. Polymorphisms (single nucleotide polymorphism [SNP]) of the glucocorticoid receptor (NR3C1) and mineralocorticoid receptor (NR3C2) associated with individual steroid sensitivity were assessed together with SNPs for 11β-hydroxysteroid dehydrogenase 1 (HSD11B1) and 11β-hydroxysteroid dehydrogenase 2 (HSD11B2). Mineralocorticoid replacement was evaluated by serum and urinary electrolytes and osmolality, plasma-renin concentration, and ambulatory blood pressure levels. We additionally measured plasma and urinary catecholamines, serum levels of IL6 and hsCRP, and SNPs of IL6 and TNF-alpha. Patient knowledge of AC prevention was assessed by questionnaires.

RESULTS

Frequent AC patients had higher daily glucocorticoid doses and hair cortisol levels, with no significant differences in other parameters investigated. AC frequency is inversely correlated with the frequency of self-reported adjustments of the glucocorticoid replacement.

CONCLUSION

Higher glucocorticoid dosages in high-risk patients, despite unaffected cortisol metabolism, may be linked to decreased cortisol sensitivity or impaired glucocorticoid absorption. Proactive dose adjustments show a protective effect against AC, regardless of biological vulnerability.

Relation between HLA and copy number variation of steroid 21-hydroxylase in a Swedish cohort of patients with autoimmune Addison's disease

OBJECTIVE

Autoantibodies against the adrenal enzyme 21-hydroxylase is a hallmark manifestation in autoimmune Addison's disease (AAD). Steroid 21-hydroxylase is encoded by CYP21A2, which is located in the human leucocyte antigen (HLA) region together with the highly similar pseudogene CYP21A1P. A high level of copy number variation is seen for the 2 genes, and therefore, we asked whether genetic variation of the CYP21 genes is associated with AAD.

DESIGN

Case-control study on patients with AAD and healthy controls.

METHODS

Using next-generation DNA sequencing, we estimated the copy number of CYP21A2 and CYP21A1P, together with HLA alleles, in 479 Swedish patients with AAD and autoantibodies against 21-hydroxylase and in 1393 healthy controls.

RESULTS

With 95% of individuals carrying 2 functional 21-hydroxylase genes, no difference in CYP21A2 copy number was found when comparing patients and controls. In contrast, we discovered a lower copy number of the pseudogene CYP21A1P among AAD patients (P = 5 × 10-44), together with associations of additional nucleotide variants, in the CYP21 region. However, the strongest association was found for HLA-DQB1*02:01 (P = 9 × 10-63), which, in combination with the DRB1*04:04-DQB1*03:02 haplotype, imposed the greatest risk of AAD.

CONCLUSIONS

We identified strong associations between copy number variants in the CYP21 region and risk of AAD, although these associations most likely are due to linkage disequilibrium with disease-associated HLA class II alleles.

Replication of association at the LPP and UBASH3A loci in a UK autoimmune Addison's disease cohort

Autoimmune Addison's disease (AAD) arises from a complex interplay between multiple genetic susceptibility polymorphisms and environmental factors. The first genome wide association study (GWAS) with patients from Scandinavian Addison's registries has identified association signals at four novel loci in the genes LPP, SH2B3, SIGLEC5, and UBASH3A. To verify these novel risk loci, we performed a case-control association study in our independent cohort of 420 patients with AAD from the across the UK. We report significant association of alleles of the LPP and UBASH3A genes [odds ratio (95% confidence intervals), 1.46 (1.21-1.75)and 1.40 (1.16-1.68), respectively] with AAD in our UK cohort. In addition, we report nominal association of AAD with SH2B3 [OR 1.18 (1.02-1.35)]. We confirm that variants at the LPP and UBASH3A loci confer susceptibility to AAD in a UK population. Further studies with larger patient cohorts are required to robustly confirm the association of SH2B3 and SIGLEC5/SPACA6 alleles.

[A Novel Pathogenic variant in NR0B1 gene associated with Congenital Adrenal Hypoplasia]

X-linked adrenal hypoplasia congenita is a rare cause of primary adrenal insufficiency. Mutations in the NR0B1 gene cause a loss of function in the DAX1 receptor, which activates genes involved in the development and function of the hypothalamic-pituitary-gonadal axis. Objective: To describe a case of adrenal hypoplasia congenita secondary to a mutation in the NR0B1 gene and identified the differential diagnoses of the pediatric patient with adrenal insufficiency and hypogonadotropic hypogonadism. Clinical Case: A 4-year-old male patient with no relevant history and from a rural area was admitted to the emergency room due to a 15-days of emesis, asthenia, adynamia, myalgia, and ataxic gait. On the physical examination, hypotension, hyponatremia, and hyperkalemia, as well as mucosal hyperpigmentation and bilateral cryptorchidism were observed, therefore, adrenal crisis was diagnosed, starting fluid resuscitation with saline solution, hydrocortisone, and fludrocortisone, which stabilized the patient. Adrenal hyperplasia congenita, innate metabolic error, and infectious or autoimmune etiology were ruled out as etiology. A clinical exome test was performed which iden tified the variant c.1275A > T; p.Arg425Ser (Transcript ENST00000378970.5) in the NR0B1 gene consistent with X-linked adrenal hypoplasia congenita. Management of the patient continued with glucocorticoids and mineralocorticoids with favorable clinical course at 7 years of follow-up. Con clusion: A novel pathogenic variant associated with X-linked adrenal hypoplasia is described. Variants in the NR0B1 gene should be a differential diagnosis in a male patient with the association of primary adrenal insufficiency and hypogonadism.

The genetics of autoimmune Addison disease: past, present and future

Autoimmune Addison disease is an endocrinopathy that is fatal if not diagnosed and treated in a timely manner. Its rarity has hampered unbiased studies of the predisposing genetic factors. A 2021 genome-wide association study, explaining up to 40% of the genetic susceptibility, has revealed new disease loci and reproduced some of the previously reported associations, while failing to reproduce others. Credible risk loci from both candidate gene and genome-wide studies indicate that, like one of its most common comorbidities, type 1 diabetes mellitus, Addison disease is primarily caused by aberrant T cell behaviour. Here, we review the current understanding of the genetics of autoimmune Addison disease and its position in the wider field of autoimmune disorders. The mechanisms that could underlie the effects on the adrenal cortex are also discussed.

Severe weight loss in a hypothyroid patient as an acute presentation of autoimmune polyglandular syndrome type II

BACKGROUND

Autoimmune disease, including autoimmune thyroid disease, with uncharacteristic symptoms can be due to additional severe disease. We report a life-threatening debut of autoimmune polyglandular syndrome type II (APS II) defined as Addison's disease combined with autoimmune diabetes and/or thyroid disease.

PATIENT FINDINGS

A 33-year-old male with newly diagnosed hypothyroidism was referred to a tertiary center due to fatigue and 20-kg rapid weight loss. Malignancy was excluded. After a gastroscopy, he developed Addison's crisis; he was admitted to our hospital and stabilized. Final diagnoses included Hashimoto's thyroiditis, Addison's disease, vitiligo, and pernicious anemia. Whole genome sequencing found no genetic variants associated with component diseases. Human leukocyte antigen typing revealed DR3/DR4 and DQ8/DQ2 heterozygosity associated with APS II. A patient with Hashimoto's thyroiditis and weight loss presented with Addison's crisis and was diagnosed with APS II.

CONCLUSIONS

Awareness of potential polyautoimmunity in clinical evaluation of patients with thyroid disease improves diagnosis and can be lifesaving.

Steroid Hormone Profiles and Molecular Diagnostic Tools in Pediatric Patients With non-CAH Primary Adrenal Insufficiency

CONTEXT

There is a significant challenge of attributing specific diagnoses to patients with primary adrenal insufficiency of unknown etiology other than congenital adrenal hyperplasia (non-CAH PAI). Specific diagnoses per se may guide personalized treatment or may illuminate pathophysiology.

OBJECTIVE

This work aimed to investigate the efficacy of steroid hormone profiles and high-throughput sequencing methods in establishing the etiology in non-CAH PAI of unknown origin.

METHODS

Pediatric patients with non-CAH PAI whose etiology could not be established by clinical and biochemical characteristics were enrolled. Genetic analysis was performed using targeted-gene panel sequencing (TPS) and whole-exome sequencing (WES). Plasma adrenal steroids were quantified by liquid chromatography-mass spectrometry and compared to that of controls. This study comprised 18 pediatric endocrinology clinics with 41 patients (17 girls, median age: 3 mo, range: 0-8 y) with non-CAH PAI of unknown etiology.

RESULTS

A genetic diagnosis was obtained in 29 (70.7%) patients by TPS. Further molecular diagnosis could not be achieved by WES. Compared to a healthy control group, patients showed lower steroid concentrations, most statistically significantly in cortisone, cortisol, and corticosterone (P < .0001, area under the receiver operating characteristic curve: .96, .88, and .87, respectively). Plasma cortisol of less than 4 ng/mL, cortisone of less than 11 ng/mL, and corticosterone of less than 0.11 ng/mL had a greater than 95% specificity to ensure the diagnosis of non-CAH PAI of unknown etiology.

CONCLUSION

Steroid hormone profiles are highly sensitive for the diagnosis of non-CAH PAI of unknown etiology, but they are unlikely to point to a specific molecular diagnosis. TPS is an optimal approach in the molecular diagnosis of these patients with high efficacy, whereas little additional benefit is expected from WES.

Can Digenic, Tri-Allelic Inheritance of Variants in STAR and CYP11A1 Give Rise to Primary Adrenal Insufficiency? A Case Report

An eight-year old South Asian boy presenting with progressive hyperpigmentation was found to have primary adrenal insufficiency (PAI) in the form of isolated glucocorticoid deficiency. Follow up of this boy for nine years, until the age of 17 years showed normal pubertal onset and progression. Molecular evaluation, by targeted next generation sequencing of candidate genes linked to PAI revealed changes in two genes that are intricately linked in the early stages of steroid biosynthesis: compound heterozygous variants in STAR, c.465+1G>A and p.(E99K), plus a heterozygous rs6161 change in CYP11A1. No variants in other known causal genes were detected. The proband's mother was heterozygous for the c.465+1G>A STAR and rs6161 CYP11A1 variants, while the father was homozygous for the p.(E99K) alteration in STAR but wild-type for CYP11A1. Both parents had normal adrenal cortical function as revealed by short Synacthen tests. The STAR variant c.465+1G>A will lead to abnormal splicing of exon 4 in mRNA and the addition of the p.(E99K) variant, predicted damaging by SIFT and CADD, may be sufficient to cause PAI but this is by no means certain given that the unaffected father is homozygous for the latter change. The rs6161 CYP11A1 variant [c.940G>A, p.(E314K)] has recently been demonstrated to cause PAI in conjunction with a severe rare disruptive change on the other allele, however sequencing of the coding region of CYP11A1 revealed no further changes in this subject. We wondered whether the phenotype of isolated glucocorticoid deficiency had arisen in this child due to tri-allelic inheritance of a heterozygous CYP11A1 change along with the two STAR variants each of which contribute a partial loss-of-function burden that, when combined, is sufficient to cause PAI or if the loss-of-function c.465+1G>A combined with the presumed partial loss-of-function p.(E99K) in STAR could be causative.

Polymorphism in BACH2 gene is a marker of polyglandular autoimmunity

PURPOSE

Genetically predisposed individuals may develop several autoimmune diseases-autoimmune polyendocrine syndromes (APS). APS types 2-4, are complex disorders, which combine various organ-specific autoimmune conditions. Recent reports support the considerable role of the BACH2 gene in immune cell differentiation and shifting the T-cell balance towards regulatory T-cells. BACH2 polymorphisms are associated with autoimmune disorders, including Addison's disease (AD), Graves' disease (GD), and probably type 1 diabetes (T1D). Our study was aimed to investigate the BACH2 variant, rs3757247, in endocrine autoimmunity in the Polish population.

METHODS

The analysis comprised 346 individuals with APS, 387 with T1D only, and 568 controls. Genotyping was performed using TaqMan chemistry.

RESULTS

APS type 2 was found in 219 individuals, type 3 in 102, and type 4 in 25 subjects. Overall, AD was diagnosed in 244 subjects, Hashimoto's thyroiditis-in 238, T1D-in 127, GD-in 58, vitiligo and chronic gastritis each in 40 patients, celiac disease-in 28, premature menopause in 18, and alopecia in 4 patients. Minor T allele at rs3757247 was found in 56.4% APS vs. 44.1% control alleles (OR 1.59; 95%CI: 1.30-1.95, p < 0.0001). The distribution of genotypes revealed excess TT homozygotes in the APS cohort (33.2 vs. 20.1% in controls, p < 0.0001). The frequencies of rs3757247 alleles and genotypes in T1D patients did not present significant differences vs. controls (p-values > 0.05).

CONCLUSIONS

These results provide evidence of the association between BACH2 polymorphism and polyglandular autoimmunity. Since carriers of rs3757247 display increased risk for additional autoimmune conditions, this variant could identify individuals prone to develop APS.

Primary Ovarian Insufficiency in Women With Addison's Disease

CONTEXT

Primary ovarian insufficiency (POI) is defined by menopause before 40 years of age. POI prevalence is higher among women with autoimmune Addison's disease (AAD) than in the general population, but their clinical characteristics are insufficiently studied.

OBJECTIVE

To assess the prevalence of POI in a large cohort of women with AAD and describe clinical, immunological, and genetic characteristics.

METHODS

An observational population-based cohort study of the Norwegian National Addison Registry. The Norwegian Prescription Database was used to assess prescription of menopausal hormone replacement therapy (HRT). A total of 461 women with AAD were studied. The primary outcome measure was prevalence of POI. Secondary outcomes were clinical characteristics, autoantibodies, and genome-wide single nucleotide polymorphism variation.

RESULTS

The prevalence of POI was 10.2% (47/461) and one-third developed POI before 30 years of age. POI preceded or coincided with AAD diagnosis in more than half of the women. The prevalence of concomitant autoimmune diseases was 72%, and AAD women with POI had more autoantibodies than AAD women without (≥2 autoantibodies in 78% vs 25%). Autoantibodies against side-chain cleavage enzyme (SCC) had the highest accuracy with a negative predictive value for POI of 96%. HRT use was high compared to the age adjusted normal population (11.3 % vs 0.7%).

CONCLUSION

One in 10 women with AAD have POI. Autoantibodies against SCC are the most specific marker for autoimmune POI. We recommend testing women with AAD <40 years with menstrual disturbances or fertility concerns for autoantibodies against SCC.

Overexpression of miR-7977 in CD4+ T cells is associated with multiplex autoimmunity in patients with Addison's disease

OBJECTIVE

Autoimmune Addison's disease (AD) results from a combination of the genetic predisposition, unclear environmental triggers and ensuing immune dysfunction. MicroRNA molecules (miRNAs) are involved in post-transcriptional regulation of numerous target genes, hence may affect the immune function and promote autoimmunity. A deregulated miRNAs profile was reported in several autoimmune conditions. Our study was aimed at a global analysis of miRNA expression in CD4+ T cells from patients with AD.

METHODS

CD4+ T cells were separated from peripheral blood, total RNA enriched in miRNAs extracted, and miRNA expression determined by small RNA sequencing. Global miRNA was investigated in 11 AD subjects and 9 age-matched healthy controls, with subsequent validation of the differentially expressed miRNAs by RT-qPCR in 29 patients and 28 controls.

RESULTS

The analysis revealed upregulation of 9 miRNAs and downregulation of miR-509-3p in CD4+ T cells from patients with AD (cut-off fold change (FC) >2, Benjamini-Hochberg P < 0.05). RT-qPCR validation confirmed overexpression of miR-7977 (P < 0.0001, FC = 2.7), miR-374a-5p and miR-1260b (P < 0.05, FC = 1.3 and 1.2, respectively). miR-7977 was upregulated in patients with coexisting autoimmune conditions vs those with isolated AD (P = 0.005, mean FC = 2.2). Moreover, miR-7977 abundance appeared correlated with the number of autoimmune comorbidities (P <0.0001, r = 0.736) and serum autoantibodies against thyroid peroxidase (P < 0.001, r = 0.588).

CONCLUSIONS

Our study demonstrates upregulated expression of miR-7977 in CD4+ T cells from patients with AD, especially with its polyendocrine form. Further analyses are warranted to replicate our results, establish the marker utility of miR-7977, and elucidate its functional role in autoimmunity.

Vitamin D status and pathway genes in five European autoimmune Addison's disease cohorts

OBJECTIVE

While vitamin D regulates immune cells, little is known about it in autoimmune Addison's disease (AAD). We investigated the vitamin D status in AAD patients from five European populations to assess its deficiency. In addition, we studied two case-control cohorts for vitamin D metabolism and pathway genes.

DESIGN

Cross-sectional study.

METHODS

A total of 1028 patients with AAD from Germany (n = 239), Italy (n = 328), Norway (n = 378), UK (n = 44) and Poland (n = 39) and 679 controls from Germany (n = 301) and Norway (n = 378) were studied for 25(OH)D3 (primary objective). Secondary objectives (1,25(OH)2D3 and pathway genes) were examined in case-controls from Germany and Norway correlating 25(OH)D3 and single nucleotide polymorphisms within genes encoding the vitamin D receptor (VDR), 1-α-hydroxylase (CYP27B1), 25-hydroxylase (CYP2R1), 24-hydroxylase (CYP24A1) and vitamin D binding protein (GC/DBP).

RESULTS

Vitamin D deficiency (25(OH)D3 10-20 ng/mL) was highly prevalent in AAD patients (34-57%), 5-22% were severely deficient (<10 ng/mL), 28-38% insufficient (20-30 ng/mL) and only 7-14% sufficient (>30 ng/mL). Lower 25(OH)D3 and 1,25(OH)2D3 levels were observed both in Norwegian and German AAD (P = 0.03/0.003 and P = 1 × 10-5/< 1 × 10-7, respectively) the former was associated with CYP2R1 (rs1553006) genotype G. Whereas controls achieved sufficient median 25(OH)D3 in summers (21.4 to 21.9 ng/mL), AAD patients remained largely deficient (18.0 to 21.2 ng/mL) and synthesize less 1,25(OH)2D3.

CONCLUSION

Vitamin D deficiency and insufficiency are highly prevalent in AAD patients. The vitamin D status of AAD may be influenced by genetic factors and suggests individual vitamin D requirements throughout the year.

Molecular Analysis of the CYP11B2 Gene in 62 Patients with Hypoaldosteronism Due to Aldosterone Synthase Deficiency

CONTEXT

Isolated congenital hypoaldosteronism presents in early infancy with symptoms including vomiting, severe dehydration, salt wasting, and failure to thrive. The main causes of this rare autosomal recessive disorder is pathogenic variants of the CYP11B2 gene leading to aldosterone synthase deficiency.

OBJECTIVE

To investigate the presence of CYP11B2 pathogenic variants in a cohort of patients with a clinical, biochemical, and hormonal profile suggestive of aldosterone synthase deficiency.

DESIGN

Clinical and molecular study.

SETTING

Tertiary academic Children's Hospital, Center for Rare Pediatric Endocrine Diseases.

PATIENTS AND METHODS

Sixty-two patients (56 unrelated patients and 6 siblings), with hypoaldosteronism and their parents, underwent CYP11B2 gene sequencing after its selective amplification against the highly homologous CYP11B1 gene. In silico analysis of the identified novel variants was carried out to evaluate protein stability and potential pathogenicity.

RESULTS

CYP11B2 gene sequencing revealed that 62 patients carried a total of 12 different pathogenic CYP11B2 gene variants, 6 of which are novel. Importantly, 96% of the 56 patients carried the previously reported p.T185I variant either in homozygosity or in compound heterozygosity with another variant. The 6 novel variants detected were: p.M1I, p.V129M, p.R141Q, p.A165T, p.R448C, and the donor splice site variant of intron 8, c.1398 + 1G > A.

CONCLUSION

Molecular diagnosis was achieved in 62 patients with aldosterone synthase deficiency, the largest cohort thus far reported. Six novel genetic variants were identified as possibly pathogenic, extending the spectrum of reported molecular defects of the CYP11B2 gene.

Genetic characterization of Addison's disease in Bearded Collies

BACKGROUND

Primary hypoadrenocorticism (or Addison's disease, AD) is an autoimmune disease that results in destruction of the adrenal cortex and consequent adrenal insufficiency. The disease has been described in purebred and mixed breed dogs, although some breeds, including the Bearded Collie, are at increased risk for AD. Candidate gene approaches have yielded few associations that appear to be breed-specific. A single other genome-wide association study reported no significant regions of association for AD in Standard Poodles. The present study aimed to identify genomic regions of association for canine AD in Bearded Collies.

RESULTS

Our study consists of the first genome-wide association analysis to identify a genome-wide significant region of association with canine AD (CFA18). Peaks of suggestive association were also noted on chromosomes 11, 16 and 29. Logistic regression analysis supported an additive effect of risk genotypes at these smaller effect loci on the probability of disease associated with carrying a risk genotype on CFA18. Potential candidate genes involved in adrenal steroidogenesis, regulation of immune responses and/or inflammation were identified within the associated regions of chromosomes 11 and 16. The gene-poor regions of chromosomes 18 and 29 may, however, harbor regulatory sequences that can modulate gene expression and contribute to disease susceptibility.

CONCLUSION

Our findings support the polygenic and complex nature of canine AD and identified a strongly associated locus on CFA18 that, when combined with three other smaller effect loci, was predictive of disease. The results offer progress in the identification of susceptibility loci for canine AD in the Bearded Collie. Further studies are needed to confirm association with the suggested candidate genes and identify actual causative mutations involved with AD susceptibility in this breed.

Identification of scavenger receptor BI as a potential screening candidate for congenital primary adrenal insufficiency in humans

Glucocorticoids belong to the superfamily of steroid hormones that are synthesized from the common precursor cholesterol. Adrenal gland-derived glucocorticoids, e.g., cortisol in humans and corticosterone in rodents, contribute to various processes essential for normal daily life. Glucocorticoid deficiency, also referred to as primary adrenal insufficiency, therefore, often becomes evident early in life and can be present with hypoglycemia, a failure to thrive, recurrent development of infections, and neurological problems, such as seizures and coma. The majority of congenital primary adrenal insufficiency cases are caused by deleterious mutations in genes involved in the intracellular mobilization of cholesterol and the subsequent conversion of cholesterol into glucocorticoids. A significant number of glucocorticoid deficiency cases, however, cannot be explained by known genetic variations. This perspective highlights existing literature regarding the importance of lipoprotein-derived cholesterol acquisition through scavenger receptor class B, type I (SR-BI/SCARB1) for the maintenance of an optimal adrenal glucocorticoid function in mice and humans. On the basis of the reviewed findings, it is suggested that the SCARB1 gene should be included in the standard glucocorticoid deficiency genetic screening panel to 1) facilitate knowledge development on the relative contribution of SR-BI-mediated cholesterol acquisition to steroid hormone synthesis in humans and 2) open up the possibility to reclassify glucocorticoid deficiency patients without a currently known genetic cause for concomitant treatment optimization.

Increased risk of endocrine autoimmunity in first-degree relatives of patients with autoimmune Addison's disease

OBJECTIVE

Autoimmune conditions tend to cluster in subjects with Addison's disease (AD) and probably also among their relatives. The aim of the study was to estimate the frequency of the endocrine gland-specific autoantibodies in first-degree relatives of patients with AD.

METHODS

Autoantibodies were investigated in 113 family members using RIA and ELISA assays. The control group comprised 143 age-matched volunteers.

RESULTS

Autoimmune diseases were diagnosed in 38.1% relatives. Hashimoto's thyroiditis was found in 20.3%, Graves' disease in 8.0%, vitiligo and type 1 diabetes in 3.5%, whereas AD, rheumatoid arthritis and atrophic gastritis with pernicious anaemia in 2.7% each. All studied antibodies except for islet antigen-2 (P = 0.085) were significantly more frequent in AD relatives than in controls (P < 0.05). Antibodies to 21-hydroxylase were detected in 6.2% relatives, thyroid peroxidase in 28.3%, thyroglobulin in 19.5%, glutamic acid decarboxylase in 8.0%, and zinc transporter-8 in 7.1%. Two and more autoantibodies were detected in 18.6% subjects. Significant gender difference was revealed only for aTPO, more common in female relatives (P = 0.014; OR: 3.16; 95% CI: 1.23-8.12). Circulating autoantibodies were found more frequently in the relatives of affected males (P = 0.008; OR: 3.31; 95% CI: 1.33-8.23), and in family members of patients with polyendocrine autoimmunity (P = 0.009; OR: 3.55; 95% CI: 1.31-9.57).

CONCLUSIONS

This study provides evidence of increased susceptibility for the endocrine autoimmunity, especially thyroid disease, in close relatives of patients with AD. Relatives of the male AD patients and of those with autoimmune polyendocrine syndrome are at particular risk and should undergo periodic screening for autoimmune endocrine disorders.

A 29-year-old patient with adrenoleukodystrophy presenting with Addison's disease

Adrenoleukodystrophy (ALD) is an X-linked disorder caused by a hemizygous mutation of the ABCD1 gene. Patients with ALD show progressive central nervous system demyelination and primary adrenal insufficiency. In Japan, most reported ALD cases were childhood-onset, and only one case of an adult patient with Addison's disease form of ALD has ever been reported. Herein, we present a case of a 29-year-old man with Addison's disease form of ALD. The patient had anorexia, weight loss, and skin pigmentation from 18 years of age. At first visit, his weight had decreased by 12 kg from 57 kg when he was 15 years old. Endocrinological examination showed low serum cortisol (1.2 μg/dL) with high plasma ACTH (4,750 pg/mL), and abdominal computed tomography showed normal adrenal glands. Very-long-chain fatty acid (VLCFA) levels were elevated, and the ABCD1 mutation, p.Gly116Arg, was identified in hemizygous state. He had no significant neurological findings on physical examination and no white matter lesions on brain magnetic resonance imaging (MRI). He was diagnosed with ALD presenting as Addison's disease, and glucocorticoid replacement therapy was initiated. Four years after the diagnosis, he still did not show any neurological findings and any white matter lesions on brain MRI. Evaluating VLCFA levels for ALD diagnosis is important in young adult men with idiopathic primary adrenal insufficiency as well as in children. Early diagnosis enables more rational approaches including the early detection of neurological complications and might improve the prognosis of patients.

Co-aggregation and heritability of organ-specific autoimmunity: a population-based twin study

OBJECTIVE

Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases.

DESIGN

Prospective twin cohort study.

METHODS

We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto's thyroiditis, atrophic gastritis, celiac disease, Graves' disease, type 1 diabetes, vitiligo and Addison's disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation of data.

RESULTS

Co-aggregation was more pronounced in monozygotic twins (median HR: 3.2, range: 2.2-9.2) than in dizygotic twins (median HR: 2.4, range: 1.1-10.0). Heritability was moderate for atrophic gastritis (0.38, 95% CI: 0.23-0.53) but high for all other diseases, ranging from 0.60 (95% CI: 0.49-0.71) for Graves' disease to 0.97 (95% CI: 0.91-1.00) for Addison's disease.

CONCLUSIONS

Overall, co-aggregation was more pronounced in monozygotic than in dizygotic twins, suggesting that disease overlap is largely attributable to genetic factors. Co-aggregation was common, and twins faced up to a ten-fold risk of developing diseases not present in their co-twin. Our results validate and refine previous heritability estimates based on smaller twin cohorts.

Beyond the adrenals: Organ manifestations in inherited primary adrenal insufficiency in children

Primary adrenal insufficiency (PAI) in children is mostly due to genetic defects. The understanding of the molecular genetics of the causes of adrenal insufficiency in the pediatric population has made significant progress during the last years. It has been shown that inherited PAI can lead to certain clinical manifestations and health problems in children beyond the adrenals. Organ dysfunctions associated with different forms of PAI in children include a wide range of organs such as gonads, brain, heart, bone, growth, bone marrow, kidney, skin, parathyroid, and thyroid. Diagnosing the correct genetic cause of PAI in children is therefore crucial to adequately control long-term treatment and follow-up in such patients.

Novel ABCD1 Gene Mutation in a Korean Patient with X-Linked Adrenoleukodystrophy Presenting with Addison's Disease

X-linked adrenoleukodystrophy (X-ALD) occurs due to mutations in the ABCD1 gene that encodes the peroxisomal membrane protein peroxisomal transporter ATP-binding cassette sub-family D member 1 (ABCD1). Degradation of very long-chain fatty acids in peroxisomes is impaired owing to ABCD dysfunction, subsequently leading to adrenomyeloneuropathy, cerebral adrenoleukodystrophy, and adrenal insufficiency. X-ALD frequently induces idiopathic Addison's disease in young male patients. Here, we confirmed the diagnosis of X-ALD in a young male patient with primary adrenal insufficiency, and identified a novel ABCD1 gene mutation (p.Trp664*, c.1991 G>A).

Primary adrenal insufficiency: New genetic causes and their long-term consequences

Primary adrenal insufficiency (PAI) is a potentially life-threatening condition that requires urgent diagnosis and treatment. Whilst the most common causes are congenital adrenal hyperplasia (CAH) in childhood and autoimmune adrenal insufficiency in adolescence and adulthood, more than 30 other physical and genetics cause of PAI have been reported. Reaching a specific diagnosis can have implications for management and for monitoring associated features, as well as for counselling families about recurrence risk in siblings and relatives. Here, we describe some recent insights into the genetics of adrenal insufficiency and associated molecular mechanisms. We discuss (a) the role of the nuclear receptors DAX-1 (NR0B1) and steroidogenic factor-1 (SF-1, NR5A1) in human adrenal and reproductive dysfunction; (b) multisystem growth restriction syndromes due to gain-of-function in the growth repressors CDKN1C (IMAGE syndrome) and SAMD9 (MIRAGE syndrome), or loss of POLE1; (c) nonclassic forms of STAR and P450scc/CYP11A1 insufficiency that present with a delayed-onset adrenal phenotype and represent a surprisingly prevalent cause of undiagnosed PAI; and (d) a new sphingolipidosis causing PAI due to defects in sphingosine-1-phosphate lyase-1 (SGPL1). Reaching a specific diagnosis can have life-long implications for management. In some situations, milder or nonclassic forms of these conditions can first present in adulthood and may have been labelled, "Addison's disease."

Novel frameshift mutation of the NR0B1(DAX1) in two tall adult brothers

NR0B1 (nuclear receptor subfamily 0, group B, member 1) is a transcription factor encoded by DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1) responsible for the development and maintenance of the steroidogenic tissues. In humans the DAX1 mutations cause congenital adrenal hypoplasia (AHC) and hypogonadotropic hypogonadism (HHG) in boys. Here we report two brothers who were assessed by endocrinologist at the age of 51 and 43 because of their serious osteoporosis. They had been substituted with prednisolone since the age of 4 and 9 years because of their primary adrenal insufficiency (PAI). Due to their late puberty caused by HHG at the age of 16 and 17 years their heights were - 3.1 and - 3.3 SD, but then they had a significant growth during their adulthood and reached the + 1.85 SD and + 3.78 SD respectively. During this period, they received glucocorticoid supplementation, but the treatment of their HHG was inadequate. At the age of 51 and 43 years insulin tolerance test (ITT) and gonadotropin releasing hormone (GnRH) test confirmed their PAI and HHG. Genetic test performed at this time revealed a novel, four nucleotides deletion (del.586-571c.GGGC or 572-575c.GGGC) of DAX1 gene. The two brothers with AHC and HHG caused by a novel DAX1 mutation, reached tall final heights, despite of the disadvantageous prednisolone treatment during their childhood. We assume that the long-term lack of the sexual hormone substitution was a significant reason of their above average height as well as their serious osteoporosis.

HLA-DQB1 Position 57 Defines Susceptibility to Isolated and Polyglandular Autoimmunity in Adults: Interaction With Gender

CONTEXT

Autoimmune endocrinopathies result from environmental triggers on the genetic background of risk alleles, especially HLA-DR and HLA-DQ with alanine (Ala) in HLA-DQB1 position 57 (Ala57), whereas amino acid Asp57 is protective.

OBJECTIVES

Differentiate the effects of HLA-DQB1 amino acid variants at position 57 in adult patients with isolated endocrinopathies and autoimmune polyglandular syndrome type 2 (APS-2) compared with healthy controls in relation to gender.

SETTING

University Hospital Frankfurt, Frankfurt, Germany.

PARTICIPANTS

Two hundred seventy-eight patients with APS-2 and 1373 patients with isolated endocrinopathies: [type 1 diabetes (T1D), n = 867], Addison disease (AD, n = 185), autoimmune thyroiditis (AIT, n = 321) and 526 healthy controls.

RESULTS

Homozygous HLA-DQB1 Ala57 was more frequent in polyglandular T1D/AIT (OR 11.7, Pc = 3 × 10-7) and AD/AIT (OR 4.0, Pc = 3 × 10-7), as well as in isolated T1D (OR 9.7, Pc = 3 × 10-7) and AD (OR 3.1, Pc = 3 × 10-7). Heterozygous HLA-DQB1 57 Ala/non-Ala was increased in women with isolated AD and polyglandular AD/AIT (both OR 1.7, Pc= 0.02) whereas the same amino acid variant was overrepresented in men with T1D compared with women (OR 1.6, Pc = 0.004). The amino acid Ala57 was more frequent (OR 2.0, Pc = 0.02) and the amino acid Asp57 was much more rare (OR 0.4, Pc = 0.007) in the APS-2 cohort T1D/AIT than in AD/AIT.

CONCLUSION

HLA-DQB1 confers strong susceptibility by Ala57 homozygosity and protection by non-Ala57, both in adult isolated and polyglandular diseases. Frequencies of HLA-DQB1 amino acids differentiate between APS-2 T1D/AIT and AD/AIT. HLA-DQB1 Ala57 heterozygous women are at increased risk for AD or AIT, whereas men were found to have an increased susceptibility for T1D.

Common genetic variation in the autoimmune regulator (AIRE) locus is associated with autoimmune Addison's disease in Sweden

Autoimmune Addison's disease (AAD) is the predominating cause of primary adrenal failure. Despite its high heritability, the rarity of disease has long made candidate-gene studies the only feasible methodology for genetic studies. Here we conducted a comprehensive reinvestigation of suggested AAD risk loci and more than 1800 candidate genes with associated regulatory elements in 479 patients with AAD and 2394 controls. Our analysis enabled us to replicate many risk variants, but several other previously suggested risk variants failed confirmation. By exploring the full set of 1800 candidate genes, we further identified common variation in the autoimmune regulator (AIRE) as a novel risk locus associated to sporadic AAD in our study. Our findings not only confirm that multiple loci are associated with disease risk, but also show to what extent the multiple risk loci jointly associate to AAD. In total, risk loci discovered to date only explain about 7% of variance in liability to AAD in our study population.

Vitamin D effects on monocytes' CCL-2, IL6 and CD14 transcription in Addison's disease and HLA susceptibility

Addison's disease is a rare autoimmune disorder leading to adrenal insufficiency and life-long glucocorticoid dependency. Vitamin D receptor (VDR) polymorphisms and vitamin D deficiency predispose to Addison's disease. Aim of the current study was, to investigate potential anti-inflammatory vitamin D effects on monocytes in Addison's disease, focusing on inflammatory CCL-2 and IL6, as well on monocyte CD14 markers. Addison's disease is genetically linked to distinct HLA susceptibility alleles. Therefore we analyzed, whether HLA genotypes differed for vitamin D effects on monocyte markers. CD14⁺ monocytes were isolated from Addison's disease patients (AD, n=13) and healthy controls (HC, n=15) and stimulated with 1,25-dihydroxyvitamin D₃ and IL1β as an inflammatory stimulant. Cells were processed for mRNA expression of CCL-2, IL6 and CD14 and DNA samples were genotyped for major histocompatibility class (MHC) class II-encoded HLA- DQA1-DQB1 haplotypes. We found a downregulation of CCL-2 after vitamin D treatment in IL1β-stimulated monocytes both from AD patients and HC (AD p<0.001; HC p<0.0001). CD14 expression however, was upregulated in both HC and AD patients after vitamin D treatment (p<0.001, respectively). HC showed higher CD14 transcription level than AD patients after vitamin D treatment (p=0.04). Compared to IL1β-induced inflammation, HC have increased CD14 levels after vitamin D treatment (p<0.001), whereas the IL1β-induced CD14 expression of AD patients' monocytes did not change after vitamin D treatment (p=0.8). AD patients carrying HLA high-risk haplotypes showed an increased CCL-2 expression after IL1β-induced inflammation compared to intermediate-risk HLA carriers (p=0.05). Also HC monocytes' CD14 transcription after IL1β and vitamin D co-stimulation differed according to HLA risk profile. We show that vitamin D can exert anti-inflammatory effects on AD patients' monocytes which may be modulated by HLA risk genotypes.

Heritability of Addison's disease and prevalence of associated autoimmunity in a cohort of 112,100 Swedish twins

PURPOSE

The pathophysiology behind autoimmune Addison's disease (AAD) is poorly understood, and the relative influence of genetic and environmental factors remains unclear. In this study, we examined the heritability of AAD and explored disease-associated autoimmune comorbidity among Swedish twins.

METHODS

A population-based longitudinal cohort of 112,100 Swedish twins was used to calculate the heritability of AAD, and to explore co-occurrence of 10 organ-specific autoimmune disorders in twin pairs with AAD. Diagnoses were collected 1964-2012 through linkage to the Swedish National Patient Register. The Swedish Prescribed Drug Register was used for additional diagnostic precision. When available, biobank serum samples were used to ascertain the AAD diagnosis through identification of 21-hydroxylase autoantibodies.

RESULTS

We identified 29 twins with AAD. Five out of nine (5/9) monozygotic pairs and zero out of fifteen (0/15) dizygotic pairs were concordant for AAD. The probandwise concordance for monozygotic twins was 0.71 (95% CI 0.40-0.90) and the heritability 0.97 (95% CI 0.88-99). Autoimmune disease patterns of monozygotic twin pairs affected by AAD displayed a higher degree of similarity than those of dizygotic twins, with an incidence rate ratio of 15 (95% CI 1.8-116) on the number of shared autoimmune diagnoses within pairs.

CONCLUSIONS

The heritability of AAD appears to be very high, emphasizing the need for further research on the genetic etiology of the disease. Monozygotic twin concordance for multiple autoimmune manifestations suggests strong genetic influence on disease specificity in organ-specific autoimmunity.

MECHANISMS IN ENDOCRINOLOGY: Update on pathogenesis of primary adrenal insufficiency: beyond steroid enzyme deficiency and autoimmune adrenal destruction

Primary adrenal insufficiency (PAI) is potentially life threatening, but rare. In children, genetic defects prevail whereas adults suffer more often from acquired forms of PAI. The spectrum of genetic defects has increased in recent years with the use of next-generation sequencing methods and now has reached far beyond genetic defects in all known enzymes of adrenal steroidogenesis. Cofactor disorders such as P450 oxidoreductase (POR) deficiency manifesting as a complex form of congenital adrenal hyperplasia with a broad clinical phenotype have come to the fore. In patients with isolated familial glucocorticoid deficiency (FGD), in which no mutations in the genes for the ACTH receptor (MC2R) or its accessory protein MRAP have been found, non-classic steroidogenic acute regulatory protein (StAR) and CYP11A1 mutations have been described; and more recently novel mutations in genes such as nicotinamide nucleotide transhydrogenase (NNT) and thioredoxin reductase 2 (TRXR2) involved in the maintenance of the mitochondrial redox potential and generation of NADPH important for steroidogenesis and ROS detoxication have been discovered. In addition, whole exome sequencing approach also solved the genetics of some syndromic forms of PAI including IMAGe syndrome (CDKN1C), Irish traveler syndrome (MCM4), MIRAGE syndrome (SAMD9); and most recently a syndrome combining FGD with steroid-resistant nephrotic syndrome and ichthyosis caused by mutations in the gene for sphingosine-1-phosphate lyase 1 (SGPL1). This review intends do give an update on novel genetic forms of PAI and their suggested mechanism of disease. It also advocates for advanced genetic work-up of PAI (especially in children) to reach a specific diagnosis for better counseling and treatment.

Does vitamin D play a role in autoimmune endocrine disorders? A proof of concept

In the last few years, more attention has been given to the "non-calcemic" effect of vitamin D. Several observational studies and meta-analyses demonstrated an association between circulating levels of vitamin D and outcome of many common diseases, including endocrine diseases, chronic diseases, cancer progression, and autoimmune diseases. In particular, cells of the immune system (B cells, T cells, and antigen presenting cells), due to the expression of 1α-hydroxylase (CYP27B1), are able to synthesize the active metabolite of vitamin D, which shows immunomodulatory properties. Moreover, the expression of the vitamin D receptor (VDR) in these cells suggests a local action of vitamin D in the immune response. These findings are supported by the correlation between the polymorphisms of the VDR or the CYP27B1 gene and the pathogenesis of several autoimmune diseases. Currently, the optimal plasma 25-hydroxyvitamin D concentration that is necessary to prevent or treat autoimmune diseases is still under debate. However, experimental studies in humans have suggested beneficial effects of vitamin D supplementation in reducing the severity of disease activity. In this review, we summarize the evidence regarding the role of vitamin D in the pathogenesis of autoimmune endocrine diseases, including type 1 diabetes mellitus, Addison's disease, Hashimoto's thyroiditis, Graves' disease and autoimmune polyendocrine syndromes. Furthermore, we discuss the supplementation with vitamin D to prevent or treat autoimmune diseases.

Genetic defects in pediatric-onset adrenal insufficiency in Japan

CONTEXT

Most patients with pediatric-onset primary adrenal insufficiency (PAI), such as 21-hydroxylase deficiency, can be diagnosed by measuring the urine or serum levels of steroid metabolites. However, the etiology is often difficult to determine in a subset of patients lacking characteristic biochemical findings.

OBJECTIVE

To assess the frequency of genetic defects in Japanese children with biochemically uncharacterized PAI and characterize the phenotypes of mutation-carrying patients.

METHODS

We enrolled 63 Japanese children (59 families) with biochemically uncharacterized PAI, and sequenced 12 PAI-associated genes. The pathogenicities of rare variants were assessed based on in silico analyses and structural modeling. We calculated the proportion of mutation-carrying patients according to demographic characteristics.

RESULTS

We identified genetic defects in 50 (85%) families: STAR in 19, NR0B1 in 18, SAMD9 in seven, AAAS in two, NNT in two, MC2R in one and CDKN1C in one. NR0B1 defects were identified in 78% of the male patients that received both glucocorticoid and mineralocorticoid replacement therapy and had normal male external genitalia. STAR defects were identified in 67% of female and 9% of male patients. Seven of the 19 patients with STAR defects developed PAI at age two or older, out of whom, five did not have mineralocorticoid deficiency.

CONCLUSIONS

Molecular testing elucidated the etiologies of most biochemically uncharacterized PAI patients. Genetic defects such as NR0B1 defects are presumed based on phenotypes, while others with broad phenotypic variability, such as STAR defects, are difficult to diagnose. Molecular testing is a rational approach to diagnosis in biochemically uncharacterized PAI patients.

A Variant in the BACH2 Gene Is Associated With Susceptibility to Autoimmune Addison's Disease in Humans

CONTEXT

Autoimmune Addison's disease (AAD) is a rare but highly heritable condition. The BACH2 protein plays a crucial role in T lymphocyte maturation, and allelic variation in its gene has been associated with a number of autoimmune conditions.

OBJECTIVE

We aimed to determine whether alleles of the rs3757247 single nucleotide polymorphism (SNP) in the BACH2 gene are associated with AAD.

DESIGN, SETTING, AND PATIENTS

This case-control association study was performed in two phases using Taqman chemistry. In the first phase, the rs3757247 SNP was genotyped in 358 UK AAD subjects and 166 local control subjects. Genotype data were also available from 5154 healthy UK controls from the Wellcome Trust (WTCCC2) for comparison. In the second phase, the SNP was genotyped in a validation cohort comprising 317 Norwegian AAD subjects and 365 controls.

RESULTS

The frequency of the minor T allele was significantly higher in subjects with AAD from the United Kingdom compared to both the local and WTCCC2 control cohorts (58% vs 45 and 48%, respectively) (local controls, P = 1.1 × 10^-4; odds ratio [OR], 1.68; 95% confidence interval [CI], 1.29-2.18; WTCCC2 controls, P = 1.4 × 10^-6; OR, 1.44; 95% CI, 1.23-1.69). This finding was replicated in the Norwegian validation cohort (P = .0015; OR, 1.41; 95% CI, 1.14-1.75). Subgroup analysis showed that this association is present in subjects with both isolated AAD (OR, 1.53; 95% CI, 1.22-1.92) and autoimmune polyglandular syndrome type 2 (OR, 1.37; 95% CI, 1.12-1.69) in the UK cohort, and with autoimmune polyglandular syndrome type 2 in the Norwegian cohort (OR, 1.58; 95% CI, 1.22-2.06).

CONCLUSION

We have demonstrated, for the first time, that allelic variability at the BACH2 locus is associated with susceptibility to AAD. Given its association with multiple autoimmune conditions, BACH2 can be considered a "universal" autoimmune susceptibility locus.

Primary Adrenocortical Insufficiency Case Series: Genetic Etiologies More Common than Expected

BACKGROUND/AIMS

Primary adrenal insufficiency (AI) is an important cause of morbidity in children. Our objectives were: (1) to describe the clinical presentation of children with new-onset primary AI, and (2) to identify monogenic causes of primary AI in children.

METHODS

Chart review and mutation detection in candidate genes were conducted for 11 patients with primary AI.

RESULTS

The likely cause of AI was determined in 9 patients. One had a homozygous MC2R mutation associated with familial glucocorticoid deficiency. Two had the same homozygous mutation in the AIRE gene which is associated with type 1 autoimmune polyglandular syndrome. One patient had a heterozygous change in this gene of undetermined significance. Five were homozygous for the previously reported p.R188C STAR mutation causing nonclassic lipoid congenital adrenal hyperplasia, representing the largest cohort of such patients from a single geographic area. In the remaining 2 patients, no clear etiology was identified.

CONCLUSIONS

We recommend genetic testing for patients who have negative anti-adrenal antibodies or suggestive family history. Diagnosing a genetic etiology can provide information about prognosis and treatment, and is therefore beneficial for patients. Our high proportion of patients with nonclassic lipoid congenital adrenal hyperplasia likely represents a founder effect.

Linkage Analysis in Autoimmune Addison's Disease: NFATC1 as a Potential Novel Susceptibility Locus

Background

Autoimmune Addison’s disease (AAD) is a rare, highly heritable autoimmune endocrinopathy. It is possible that there may be some highly penetrant variants which confer disease susceptibility that have yet to be discovered.

Methods

DNA samples from 23 multiplex AAD pedigrees from the UK and Norway (50 cases, 67 controls) were genotyped on the Affymetrix SNP 6.0 array. Linkage analysis was performed using Merlin. EMMAX was used to carry out a genome-wide association analysis comparing the familial AAD cases to 2706 UK WTCCC controls. To explore some of the linkage findings further, a replication study was performed by genotyping 64 SNPs in two of the four linked regions (chromosomes 7 and 18), on the Sequenom iPlex platform in three European AAD case-control cohorts (1097 cases, 1117 controls). The data were analysed using a meta-analysis approach.

Results

In a parametric analysis, applying a rare dominant model, loci on chromosomes 7, 9 and 18 had LOD scores >2.8. In a non-parametric analysis, a locus corresponding to the HLA region on chromosome 6, known to be associated with AAD, had a LOD score >3.0. In the genome-wide association analysis, a SNP cluster on chromosome 2 and a pair of SNPs on chromosome 6 were associated with AAD (P <5x10^-7). A meta-analysis of the replication study data demonstrated that three chromosome 18 SNPs were associated with AAD, including a non-synonymous variant in the NFATC1 gene.

Conclusion

This linkage study has implicated a number of novel chromosomal regions in the pathogenesis of AAD in multiplex AAD families and adds further support to the role of HLA in AAD. The genome-wide association analysis has also identified a region of interest on chromosome 2. A replication study has demonstrated that the NFATC1 gene is worthy of future investigation, however each of the regions identified require further, systematic analysis.

Focus on vitamin D and the adrenal gland

The main role of vitamin D is to maintain calcium and phosphorus homeostasis, thus preserving bone health. However, recent evidences have demonstrated that vitamin D may also play a role in a variety of nonskeletal disorders such as endocrine diseases and in particular type 1 diabetes, type 2 diabetes, adrenal diseases, and the polycystic ovary syndrome. Despite controversial results on an association of low vitamin D levels with cortisol and aldosterone overproduction, encouraging in vitro findings have been reported on vitamin D effects in adrenocortical cancer cells. The focus of this review is the role of vitamin D in adrenal diseases and the results of vitamin D supplementation studies in patients. Although many studies support a beneficial role of vitamin D in adrenal disease, randomized controlled trials and mechanistic studies are required to provide more insight into the efficacy and safety of vitamin D as a therapeutic tool.

Role of the X-linked gene GPR174 in autoimmune Addison's disease

CONTEXT

Autoimmune endocrinopathies demonstrate a profound gender bias, but the reasons for this remain obscure. The 1000 genes on the X chromosome are likely to be implicated in this inherent susceptibility; various theories, including skewed X chromosome inactivation and fetal microchimerism, have been proposed. GPR174 is an Xq21 putative purinergic receptor that is widely expressed in lymphoid tissues. A single-nucleotide polymorphism, rs3827440, encoding Ser162Pro, has recently been associated with Graves' disease in Chinese and Polish populations, suggesting a role of this X chromosome gene in autoimmune disease.

OBJECTIVE

We investigated the role of rs3827440 in a UK cohort of patients with autoimmune Addison's disease (AAD). Samples from 286 AAD cases and 288 healthy controls were genotyped using TaqMan single-nucleotide polymorphism genotyping assays (C_25954273_10) on the Applied Biosystems 7900HT Fast real-time PCR system.

DESIGN

Using a dominant (present/absent) model, the serine-encoding T allele of rs3827440 was present in 189 of 286 AAD patients (66%) compared with 132 of 288 unaffected controls (46%) [P = .010, odds ratio 1.80 (5%-95% confidence interval 1.22-2.67)]. An allele dosage model found a significant excess of the T allele in AAD patients compared with controls [P = .03, odds ratio 1.34 (5%-95% confidence interval 1.07-1.67)].

CONCLUSION

We have demonstrated a significant association of this X chromosome-encoded immunoreceptor with AAD for the first time. This X-linked gene could have a more generalized role in autoimmunity pathogenesis: G protein-coupled receptors are promising drugable targets, and further work to elucidate the functional role of GPR174 is now warranted.

CYP21A2 polymorphisms in patients with autoimmune Addison's disease, and linkage disequilibrium to HLA risk alleles

OBJECTIVE

Steroid 21-hydroxylase, encoded by CYP21A2, is the major autoantigen in autoimmune Addison's disease (AAD). CYP21A2 is located in the region of the HLA complex on chromosome 6p21.3, which harbours several risk alleles for AAD. The objective was to investigate whether CYP21A2 gene variants confer risk of AAD independently of other risk alleles in the HLA loci.

DESIGN

DNA samples from 381 Norwegian patients with AAD and 340 healthy controls (HC) previously genotyped for the HLA-A, -B, -DRB1, and -DQB1 and MICA loci were used for genotyping of CYP21A2.

METHODS

Genotyping of CYP21A2 was carried out by direct sequencing. Linkage of CYP21A2 to the HLA loci was assessed using UNPHASED version 3.0.10 and PHASE version 2.1.

RESULTS

Heterozygotes of the single-nucleotide polymorphisms (SNPs) rs397515394, rs6467, rs6474, rs76565726 and rs6473 were detected significantly more frequently in AAD patients compared with HC (P<0.005), but all SNPs were in a linkage disequilibrium (LD) with high-risk HLA-DRB1 haplotypes. rs6472C protected against AAD (odds ratio=0.15, 95% CI (0.08-0.30), P=3.8×10(-10)). This SNP was not in an LD with HLA loci (P=0.02), but did not increase protection when considering the effect of HLA-DRB1 alleles. Mutations causing congenital adrenal hyperplasia were found in heterozygosity in <1.5% of the cases in both groups.

CONCLUSION

Genetic variants of CYP21A2 associated to AAD are in LD with the main AAD risk locus HLA-DRB1, and CYP21A2 does not constitute an independent susceptibility locus.

Addison's disease: a survey on 633 patients in Padova

OBJECTIVE

Addison's disease (AD) is a rare endocrine condition.

DESIGN

We aimed to evaluate clinical, immunologic, adrenal imaging, and genetic features in 633 Italian patients with AD followed up since 1967.

METHODS

Adrenal cortex autoantibodies, presence of other autoimmune and nonautoimmune diseases, nonadrenal autoantibodies, adrenal imaging, and genetic profile for HLA-DRB1 and AIRE were analyzed.

RESULTS

A total of 492 (77.7%) patients were found to be affected by autoimmune AD (A-AD), 57 (9%) tuberculous AD, 29 (4.6%) genetic-associated AD, 10 (1.6%) adrenal cancer, six (0.94%) post-surgical AD, four (0.6%) vascular disorder-related AD, three (0.5%) post-infectious AD, and 32 (5.1%) were defined as idiopathic. Adrenal cortex antibodies were detected in the vast majority (88100%) of patients with recent onset A-AD, but in none of those with nonautoimmune AD. Adrenal imaging revealed normal/atrophic glands in all A-AD patients: 88% of patients with A-AD had other clinical or subclinical autoimmune diseases or were positive for nonadrenal autoantibodies. Based on the coexistence of other autoimmune disorders, 65.6% of patients with A-AD were found to have type 2 autoimmune polyendocrine syndrome (APS2), 14.4% have APS1, and 8.5% have APS4. Class II HLA alleles DRB1*03 and DRB1*04 were increased, and DRB1*01, DRB1*07, DRB1*013 were reduced in APS2 patients when compared with controls. Of the patients with APS1, 96% were revealed to have AIRE gene mutations.

CONCLUSIONS

A-AD is the most prevalent form of adrenal insufficiency in Italy, and ∼90% of the patients are adrenal autoantibody-positive at the onset. Assessment of patients with A-AD for the presence of other autoimmune diseases should be helpful in monitoring and diagnosing APS types 1, 2, or 4 and improving patients' care.

MicroRNA expressions in PMBCs, CD4+, and CD8+ T-cells from patients suffering from autoimmune Addison's disease

Autoimmune Addison's disease (AD) is a rare but potentially life threatening disease. The exact etiology of the immune response to the adrenal gland is still unknown. MicroRNAs (miRNAs) critically control gene-expression and play an important role in regulating the immune response. The aim of this study was to determine key immunoregulatory miRNAs influencing autoimmune adrenal insufficiency. For this purpose selected miRNAs were amplified by a semiquantitative SYBR Green PCR from blood mononuclear cells and after purification from CD4+ and CD 8+ cells of 6 patients with autoimmune adrenal insufficiency and 10 healthy controls. In CD4+ T-cells miRNA 181a*_1 (18.02 in AD vs. 11.99 in CG, p=0.0047) is significantly increased whereas miRNA 200a_1 (12.48 in AD vs. 19.40 in CG, p=0.0003) and miRNA 200a_2* (8.59 in AD vs. 17.94 in CG, p=0.0160) are significantly decreased. miRNA 200a_1 (12.37 in AD group vs. 18.12 in control group, p=0.001) and miRNA 200a_2* (10.72 in AD group vs. 17.84 in control group, p=0.022) are also significantly decreased in CD8+ T-cells. This study could show for the first time a significant change of three defined miRNAs in PBMCs, CD4+, and CD8+ T-cells of autoimmune AD patients in vivo. These data may help to better understand the cause of the autoimmune processes leading to autoimmune AD. They extend our very limited knowledge concerning miRNAs in autoimmune Addison's disease.

BclI polymorphism of the glucocorticoid receptor gene is associated with increased bone resorption in patients on glucocorticoid replacement therapy

CONTEXT

Patients with primary adrenal insufficiency (PAI) and patients with congenital adrenal hyperplasia (CAH) receive weight-adapted standard glucocorticoid replacement therapy. Clinically, some patients appear more sensitive to therapeutic administration of glucocorticoids than others. Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR) and might influence bone mineral density (BMD).

OBJECTIVES

To determine if bone turnover markers and BMD are associated with the GR gene polymorphism BclI in patients with PAI and CAH.

DESIGN AND PATIENTS

A prospective, cross-sectional study including 74 PAI and 38 CAH patients. BMD was evaluated by DXA. Serum levels of bone turnover markers, minerals, vitamins and hormones, and urinary crosslinks were measured.

RESULTS

Patients carrying the homozygous BclI polymorphism (GG) had significantly higher serum β-CrossLaps (0.37 ± 0.34 μg/l; P < 0.05) and urinary collagen crosslinks (NTX, 68.1 ± 32.4 nmol/g; P < 0.005) despite receiving the lowest average daily hydrocortisone dose of 9.9 ± 3.7 mg/m(2) (P < 0.05). The GG genotype occurred significantly more frequently in patients with increased NTX (OR=6.7, 95% CI = 1.78-25.38) than in patients with normal NTX. However, BMD was not significantly different between different allelic variants. No significant differences in associations of the genotypes with outcomes (or in clinical characteristics) were found between the sexes.

CONCLUSIONS

Although the sample sizes were relatively small and the results should be interpreted with caution, this study suggests that the homozygous (GG) genotype may be associated with higher bone resorption in adult PAI and CAH patients. GG-carriers needed a lower hydrocortisone dose on average supporting the concept that this GR variant is associated with increased cortisol sensitivity.

Investigation of glucocorticoid receptor polymorphisms in relation to metabolic parameters in Addison's disease

BACKGROUND

Uncertainty exists whether glucocorticoid receptor (GCR) polymorphisms play a role in steroid-related side effects in Addison's disease (AD) patients on hydrocortisone. The polymorphisms Bcll and N363S appear to increase sensitivity to cortisol, while the ER22/23EK polymorphism has been associated with resistance to cortisol.

METHOD

One hundred and forty seven AD patients, and gender, and ethnicity-matched controls were recruited in South Africa. Three polymorphisms in the GCR were studied, using PCR followed by restriction fragment length analysis. Associations with BMI, lipids, glucose and inflammatory markers were investigated.

RESULTS

In both patients and controls, the Bcll polymorphism occurred more frequently in whites than in other ethnic groups studied but was not associated with any of the metabolic parameters tested. The ER22/23EK polymorphism was associated with an increased BMI in both patients (29.4 vs 24.7  kg/m²) and control subjects (26.3 vs 24.2  kg/m²). The ER22/23EK polymorphism was also associated with lower LDL cholesterol in control subjects (3.46 vs 3.93  mmol/l) and in patients (3.52 vs 4.10  mmol/l). N363S was associated with increased BMI in controls 29.9  kg/m² vs wild type 24.8  kg/m². Median hydrocortisone doses were greater in patients heterozygous for either ER22/23EK 30.0  mg or N363S 25.0  mg polymorphisms than in wild type patients 20.0  mg (both comparisons).

CONCLUSION

Alterations in lipids, BMI and hydrocortisone dose were associated with two polymorphisms. Further larger studies are warranted to corroborate these findings.

Polymorphisms in the interferon-induced helicase (IFIH1) locus and susceptibility to Addison's disease

OBJECTIVE

The interferon-induced helicase C domain-containing protein 1 (IFIH1) gene encodes a sensor for double-stranded RNA that initiates antiviral activity against enteroviruses. Previous investigations have indicated a role for IFIH1 in autoimmunity, as common and rare polymorphisms in this gene have been associated with type 1 diabetes. We hypothesized that polymorphisms in the IFIH1 locus may play a role in the pathogenesis of autoimmune Addison's disease (AAD).

DESIGN

We analysed the association of rs3747517, rs1990760, rs2111485 and rs13422767 single-nucleotide polymorphisms (SNPs) in the IFIH1 gene and intergenic region with AAD in a Polish cohort. The study comprised 120 patients with AAD and 689 healthy control individuals. Genotyping was performed using TaqMan genotyping assays.

RESULTS

The major AA genotype of the coding SNP rs1990760 appeared significantly more frequently in AAD compared with healthy individuals (AG vs AA OR 0·62, 95%CI 0·40-0·95, P = 0·03). We also observed a significant difference in the distribution of the rs13422767 SNP alleles. The major G allele was more frequent in the AAD group (A vs G OR 0·65, 95%CI 0·43-0·98, P = 0·04). Both statistically significant differences, for rs1990760 and rs13422767 SNPs, did not survive the Bonferroni correction (P = 0·11 and P = 0·15, for AA genotype and G allele, respectively). Subsequently, a meta-analysis of 519 patients with AAD and 1362 controls from three different European populations was performed. Under a fixed-effect model, a pooled OR for A allele and AA genotype of rs1990760 did not display any significant increase among AAD (OR = 1·05, P = 0·56 and OR = 1·08, P = 0·50, respectively).

CONCLUSION

The IFIH1 locus polymorphisms are unlikely to be associated with Addison's disease.

Bioinactive ACTH causing glucocorticoid deficiency

CONTEXT

A 4-year-old girl and a 4-month-old boy presented with hypoglycemia, normal electrolytes, low cortisol, and high ACTH. A diagnosis of primary adrenal insufficiency was made and initial treatment was with glucocorticoids and mineralocorticoids. The genes known to cause ACTH resistance were normal. Whole exome sequencing revealed that the girl was compound heterozygous for POMC mutations: one previously described null allele and one novel p.R8C mutation in the sequence encoding ACTH and α-MSH. The boy was homozygous for the p.R8C mutation.

HYPOTHESIS

The p.R8C ACTH mutant is immunoreactive, but the mutant peptides, ACTH-R8C and α-MSH-R8C, are bioinactive.

METHODS

Methods included whole exome sequencing, Sanger sequencing, peptide synthesis, ACTH immunoradiometric assay, hormone binding, and activation assays in cells expressing melanocortin receptors.

RESULTS

ACTH-R8C was immunoreactive but failed to bind and activate cAMP production in melanocortin-2 receptor (MC2R)-expressing cells, and α-MSH-R8C failed to bind and stimulate cAMP production in MC1R- and MC4R-expressing cells.

CONCLUSION

These are the first documented cases of glucocorticoid deficiency due to the secretion of an ACTH molecule that lacks biological bioactivity but conserves immunoreactivity. POMC mutations should thus be considered in patients presenting with apparent ACTH resistance. Our findings also highlight a limitation to immunoassay-based diagnostics and demonstrate the value of genetic analysis. Establishing the molecular etiology of the disorder in our patients allowed cessation of the unnecessary mineralocorticoids. Finally, discovery of this mutation indicates that in humans, the amino acid sequence His(6)Phe(7)Arg(8)Trp(9) is important not only for cAMP activation but also for ACTH binding to MC2R.

Peculiar genotypes of the autoimmune regulator gene in Italian patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome

BACKGROUND

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is due to mutations in the autoimmune regulator gene (AIRE). The highest number of patients was reported in Finland and among other ethnic groups such as Iranian Jews. Hot spots of incidence are also in Italian regions including Sardinia, Apulia, and the Venetian region, where peculiar AIRE genotypes were identified.

METHODS

We conducted screenings of all the 14 exons of the AIRE gene in 5 APECED patients from 3 different Italian regions.

RESULTS

We confirmed the peculiar Sardinian R139X genotype in 2 Sardinians and unusually in one patient from the Venetian region. As expected, exon 1 mutation was detected in one patient from Campania, while the other with the novel c.1314-1326del13/insGT mutation in exon 11 and already described, presented candidiasis and autoimmune hepatitis as first symptoms. No genotype/phenotype correlation was observed in the remaining patients.

CONCLUSIONS

Testing AIRE genotypes is useful to confirm an APECED diagnosis but also in investigating the pathogenesis and epidemiology of the disease in different regions.